HHH-7279

hibernate-core/src/main/java/org/hibernate/engine/internal/StatefulPersistenceContext.java

@@ -1801,6 +1801,9 @@ public class StatefulPersistenceContext implements PersistenceContext {
 				CachedNaturalIdValueSource source) {
 			final NaturalIdRegionAccessStrategy naturalIdCacheAccessStrategy = persister.getNaturalIdCacheAccessStrategy();
 			final NaturalIdCacheKey naturalIdCacheKey = new NaturalIdCacheKey( naturalIdValues, persister, session );
+			if (naturalIdCacheAccessStrategy.get(naturalIdCacheKey, session.getTimestamp()) != null) {
+				return; // prevent identical re-cachings
+			}
 
 			final SessionFactoryImplementor factory = session.getFactory();
 

hibernate-core/src/matrix/java/org/hibernate/test/naturalid/mutable/cached/Another.java

@@ -39,6 +39,7 @@ import org.hibernate.annotations.NaturalIdCache;
 public class Another {
 	private Integer id;
 	private String name;
+	private String surname;
 
 	public Another() {
 	}
@@ -66,4 +67,12 @@ public class Another {
 	public void setName(String name) {
 		this.name = name;
 	}
+
+	public String getSurname() {
+		return surname;
+	}
+
+	public void setSurname(String surname) {
+		this.surname = surname;
+	}
 }

hibernate-core/src/matrix/java/org/hibernate/test/naturalid/mutable/cached/CachedMutableNaturalIdTest.java

@@ -23,6 +23,8 @@
  */
 package org.hibernate.test.naturalid.mutable.cached;
 
+import java.io.Serializable;
+
 import org.junit.Test;
 
 import org.hibernate.Session;
@@ -225,5 +227,40 @@ public class CachedMutableNaturalIdTest extends BaseCoreFunctionalTestCase {
 		
 		assertEquals(0, session.getSessionFactory().getStatistics().getNaturalIdCacheHitCount());
 	}
+	
+	@Test
+	public void testNaturalIdRecachingWhenNeeded() {
+		Session session = openSession();
+		session.getSessionFactory().getStatistics().clear();
+		session.beginTransaction();
+		Another it = new Another( "it");
+		session.save( it );
+		Serializable id = it.getId();
+		session.getTransaction().commit();
+		session.close();
+		
+		session = openSession();
+		for (int i=0; i < 10; i++) {
+			session.beginTransaction();
+			it = (Another) session.byId(Another.class).load(id);
+			if (i == 9) {
+				it.setName("name" + i);
+			}
+			it.setSurname("surname" + i); // changing something but not the natural-id's
+			session.getTransaction().commit();
+		}
+		
+		session = openSession();
+		session.beginTransaction();
+		it = (Another) session.bySimpleNaturalId(Another.class).load("it");
+		assertNull(it);
+		assertEquals(0, session.getSessionFactory().getStatistics().getNaturalIdCacheHitCount());
+		it = (Another) session.byId(Another.class).load(id);
+		session.delete(it);
+		session.getTransaction().commit();
+		
+		// finally there should be only 2 NaturalIdCache puts : 1. insertion, 2. when updating natural-id from 'it' to 'name9'
+		assertEquals(2, session.getSessionFactory().getStatistics().getNaturalIdCachePutCount());
+	}
 }